Tissue engineering is an example of an area where the attachment of disparate biomaterials is of interest. Tissue engineering and regenerative medicine approaches have been extensively employed to treat conditions (such as single-tissue orthopedic defects) through the use of functional biomimetic biomaterials,1-5 with more emphasis towards the interface.6 
Although the interdisciplinary field of tissue engineering holds great promise for the treatment of numerous conditions, various serious limitations remain that prevent the effective use of current techniques in the regeneration of certain tissues. For instance, the regeneration of cartilage by current tissue engineering approaches has proven to be challenging because cartilage has a very limited regenerative capacity. Articular cartilage in joints is relatively avascular, contains few native mature cells (chondrocytes) and possesses a gradient of properties from the synovial surface to the subchondral bone. These characteristics are distinctly different from the highly vascularized and heavily cell populated composition of bone. In addition, there is a complex interface between cartilage and subchondral bone. The treatment of damaged tissues at interfaces, like the osteochondral interface, is particularly difficult due to the presence of biological and chemical gradients, namely: cell population(s), tissue type, and extracellular matrix (ECM) proteins are often present and difficult to recapitulate. The osteochondral interface is of great importance since it is a site of attachment between two distinct tissues while providing the necessary structure and mechanical integrity for energy transfer.
Interfacial tissue engineering (ITE) is one approach to address the complex bi- or multiphasic nature of osteochondral defects. This serves to introduce the main caveat of ITE, where interfaces have shared characteristics of the tissues being connected but also contains regions of distinct composition and biological function.7 As a result, the development of new methods, biomaterials, and techniques to manufacture biomimetic constructs linking two distinct tissues within certain biological and mechanical constraints presents considerable challenges. In addition, it is important to note that natural human osteochondral tissue ECM is in the nanometer dimension range and is composed of many nanostructured components (such as nanocrystalline hydroxyapatites, collagen and various other proteins).8 